Dihydroperimidine-derived PNP pincer complexes as intermediates en route to N-heterocyclic carbene pincer complexes

Anthony F. Hill; Caitlin M.A. McQueen

doi:10.1021/om5000985

Dihydroperimidine-derived PNP pincer complexes as intermediates en route to N-heterocyclic carbene pincer complexes

Anthony F. Hill^*, Caitlin M.A. McQueen

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

31 Citations (Scopus)

Abstract

The reaction of N,N′-bis(dicyclohexylphosphinomethyl) dihydroperimidine (H₂C(NCH₂PCy₂) ₂C₁₀H₆-1,8, 1a) with [RuCl₂(PPh ₃)₃] in THF affords the perimidinylidene-based N-heterocyclic carbene (per-NHC) pincer complex [RuCl₂(OC ₄H₈){=C(NCH₂PCy₂)₂C ₁₀H₆}] (2) via chelate-assisted double C-H activation. In contrast, the reactions of the tetraphenyl analogue H₂C(NCH ₂PPh₂)₂C₁₀H₆ (1b) with [RuCl₂(PPh₃)₃] and of 1a with [RuCl(R)(CO)(PPh₃)₂] (R = Ph, CH=CHPh) do not result in C-H activation but rather give the asymmetric, PNP-coordinated complexes [RuCl₂(PPh₃){κ³P,N,P′-CH ₂(NCH₂PPh₂)₂C₁₀H ₆}] (3) and [RuCl(R)(CO){κ³P,N,P′-CH ₂(NCH₂PCy₂)₂C₁₀H ₆}] (R = Ph (4), CH=CHPh (5)), respectively, in which the ruthenium migrates rapidly between nitrogen donors. This provides insight into the mechanistic pathway by which the proligands 1 undergo per-NHC formation, as demonstrated by the thermal conversion of 4 to [RuHCl(CO){=C(NCH ₂PCy₂)₂C₁₀H₆}] (6) and benzene.

Original language	English
Pages (from-to)	1909-1912
Number of pages	4
Journal	Organometallics
Volume	33
Issue number	8
DOIs	https://doi.org/10.1021/om5000985
Publication status	Published - 28 Apr 2014

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@article{185362f43b974118a3652fe467cd67c0,

title = "Dihydroperimidine-derived PNP pincer complexes as intermediates en route to N-heterocyclic carbene pincer complexes",

abstract = "The reaction of N,N′-bis(dicyclohexylphosphinomethyl) dihydroperimidine (H2C(NCH2PCy2) 2C10H6-1,8, 1a) with [RuCl2(PPh 3)3] in THF affords the perimidinylidene-based N-heterocyclic carbene (per-NHC) pincer complex [RuCl2(OC 4H8){=C(NCH2PCy2)2C 10H6}] (2) via chelate-assisted double C-H activation. In contrast, the reactions of the tetraphenyl analogue H2C(NCH 2PPh2)2C10H6 (1b) with [RuCl2(PPh3)3] and of 1a with [RuCl(R)(CO)(PPh3)2] (R = Ph, CH=CHPh) do not result in C-H activation but rather give the asymmetric, PNP-coordinated complexes [RuCl2(PPh3){κ3P,N,P′-CH 2(NCH2PPh2)2C10H 6}] (3) and [RuCl(R)(CO){κ3P,N,P′-CH 2(NCH2PCy2)2C10H 6}] (R = Ph (4), CH=CHPh (5)), respectively, in which the ruthenium migrates rapidly between nitrogen donors. This provides insight into the mechanistic pathway by which the proligands 1 undergo per-NHC formation, as demonstrated by the thermal conversion of 4 to [RuHCl(CO){=C(NCH 2PCy2)2C10H6}] (6) and benzene.",

author = "Hill, {Anthony F.} and McQueen, {Caitlin M.A.}",

year = "2014",

month = apr,

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doi = "10.1021/om5000985",

language = "English",

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journal = "Organometallics",

issn = "0276-7333",

publisher = "American Chemical Society",

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TY - JOUR

T1 - Dihydroperimidine-derived PNP pincer complexes as intermediates en route to N-heterocyclic carbene pincer complexes

AU - Hill, Anthony F.

AU - McQueen, Caitlin M.A.

PY - 2014/4/28

Y1 - 2014/4/28

N2 - The reaction of N,N′-bis(dicyclohexylphosphinomethyl) dihydroperimidine (H2C(NCH2PCy2) 2C10H6-1,8, 1a) with [RuCl2(PPh 3)3] in THF affords the perimidinylidene-based N-heterocyclic carbene (per-NHC) pincer complex [RuCl2(OC 4H8){=C(NCH2PCy2)2C 10H6}] (2) via chelate-assisted double C-H activation. In contrast, the reactions of the tetraphenyl analogue H2C(NCH 2PPh2)2C10H6 (1b) with [RuCl2(PPh3)3] and of 1a with [RuCl(R)(CO)(PPh3)2] (R = Ph, CH=CHPh) do not result in C-H activation but rather give the asymmetric, PNP-coordinated complexes [RuCl2(PPh3){κ3P,N,P′-CH 2(NCH2PPh2)2C10H 6}] (3) and [RuCl(R)(CO){κ3P,N,P′-CH 2(NCH2PCy2)2C10H 6}] (R = Ph (4), CH=CHPh (5)), respectively, in which the ruthenium migrates rapidly between nitrogen donors. This provides insight into the mechanistic pathway by which the proligands 1 undergo per-NHC formation, as demonstrated by the thermal conversion of 4 to [RuHCl(CO){=C(NCH 2PCy2)2C10H6}] (6) and benzene.

AB - The reaction of N,N′-bis(dicyclohexylphosphinomethyl) dihydroperimidine (H2C(NCH2PCy2) 2C10H6-1,8, 1a) with [RuCl2(PPh 3)3] in THF affords the perimidinylidene-based N-heterocyclic carbene (per-NHC) pincer complex [RuCl2(OC 4H8){=C(NCH2PCy2)2C 10H6}] (2) via chelate-assisted double C-H activation. In contrast, the reactions of the tetraphenyl analogue H2C(NCH 2PPh2)2C10H6 (1b) with [RuCl2(PPh3)3] and of 1a with [RuCl(R)(CO)(PPh3)2] (R = Ph, CH=CHPh) do not result in C-H activation but rather give the asymmetric, PNP-coordinated complexes [RuCl2(PPh3){κ3P,N,P′-CH 2(NCH2PPh2)2C10H 6}] (3) and [RuCl(R)(CO){κ3P,N,P′-CH 2(NCH2PCy2)2C10H 6}] (R = Ph (4), CH=CHPh (5)), respectively, in which the ruthenium migrates rapidly between nitrogen donors. This provides insight into the mechanistic pathway by which the proligands 1 undergo per-NHC formation, as demonstrated by the thermal conversion of 4 to [RuHCl(CO){=C(NCH 2PCy2)2C10H6}] (6) and benzene.

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U2 - 10.1021/om5000985

DO - 10.1021/om5000985

M3 - Article

SN - 0276-7333

VL - 33

SP - 1909

EP - 1912

JO - Organometallics

JF - Organometallics

IS - 8

ER -

Dihydroperimidine-derived PNP pincer complexes as intermediates en route to N-heterocyclic carbene pincer complexes

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